Add a simple way to remove items from a collection.

[joakim-eriksson]

With the latest changes there is no easy and clean way to remove or replace items from a collection. Before one would always get a mutable collection when using the get methods, this has now changed. Maybe add remove and replace methods to the generated builders.

[Jordan Zimmerman]

Can you give a quick code example of how you were using it before?

[joakim-eriksson]

I have changed my mind on this, more advanced features of the collection classes is better handled outside of the builder.